DEMO Dark Rift Delay (EQD Space Spiral)

[owlexifry]

omg.
the noise.

how did i not see all these threads:
https://forum.pedalpcb.com/threads/...ion-fuzz-in-wet-signal.3512/page-3#post-41773
https://forum.pedalpcb.com/threads/dark-rift-delay-noise-in-the-repeats.4557/
https://forum.pedalpcb.com/threads/dark-rift-noise.4069/
https://forum.pedalpcb.com/threads/dark-rift.19252/
https://forum.pedalpcb.com/threads/dark-rift-noise.24338/

so i missed all of that, and just built as per the silkscreen.


(my white pen has stopped working)

fired it up and was monumentally disappointed. noisiest repeats ever.
tried a heap of different PT2399s.
nah, no good.
i thought maybe i’d made an error or something.
but i searched the forum, found all the threads, and well, i have no words. wtf EQD (especially when you read chuck bones' comments on the matter).

the main solution appears to be adjusting values for R7, R18 and R13.
R13 - sets the output gain.
R18 - limits the dry signal.
R7 - limits the input signal to the PT2399 pin 16.

MODS:
R13: 33K (chose this for more output)
R18: 27K (just went with the suggestion)
R7: 27K (actually tried different values on a breadboard (10K, 15K, 18K, 20K, 22K) to see what i could get away with, but it appears the suggested 27K value is on point here (at least for humbuckers).



after all that, it sounds pretty good.

while the magnetron and seabed are solid choices as straight-up tape style delays, the modulations on this dark rift are a real delight. (where, comparably, the modulations on the magnetron may as well not exist)

here's a demo

 

[Erik S]

That sounds great!

My noisy Dark Rift was the reason I was so surprised that the Magnetron was so good. I guess I just assumed all that noise was part of the price of admission for pt2399 delays.

Sounds like I need to open mine back up and try those mods out.

 

[jcpst]

I had similar thoughts- it cool when you get past the issues, but it’s like “why is the stock circuit so wonky?”

I had good luck on the third PT2399 I tried. But it also introduced a nasty clip on the repeaats. The forum solution for that is a green LED on pin 7 and ground.

Having trouble finding the original post, but here’s a reference to it.

Post in thread 'Dark Rift'
https://forum.pedalpcb.com/threads/dark-rift.19252/post-236679

Also, I used the same hammered silver enclosure! Nice choice

Thread 'Dark Rift Delay'
https://forum.pedalpcb.com/threads/dark-rift-delay.21941/

 

[KreoPensas]

It's worth building a minimum test circuit for pt2399's so you can audition them. I grabbed Synthrotek's little pt2399 dev board and crammed a ZIF socket on to it.

I built Jed's Ped's version, so far it is my favorite modulated delay. I switched the diodes to D9E just to be cheeky.

 

[owlexifry]

That sounds great!

My noisy Dark Rift was the reason I was so surprised that the Magnetron was so good. I guess I just assumed all that noise was part of the price of admission for pt2399 delays.

Sounds like I need to open mine back up and try those mods out.

cheers
yeah it’s a PITA to fix up and do these mods after it’s already boxed it up, but i reckon it’s worth it for the lush modulations this is capable of..
(i also figured out i could just bend the pot out of the way to desolder the resistors instead of desoldering a whole pot)

I had similar thoughts- it cool when you get past the issues, but it’s like “why is the stock circuit so wonky?”

yep, it’s a real doozy.

I had good luck on the third PT2399 I tried. But it also introduced a nasty clip on the repeaats. The forum solution for that is a green LED on pin 7 and ground.

Having trouble finding the original post, but here’s a reference to it.

Post in thread 'Dark Rift'
https://forum.pedalpcb.com/threads/dark-rift.19252/post-236679

yeah i saw the suggestions about a green LED on pin 7 and ground to resolve clipping, but to me that appeared a little bit crude than making adjustments to x3 R values

Also, I used the same hammered silver enclosure! Nice choice

Thread 'Dark Rift Delay'
https://forum.pedalpcb.com/threads/dark-rift-delay.21941/

ayy sweet!

It's worth building a minimum test circuit for pt2399's so you can audition them. I grabbed Synthrotek's little pt2399 dev board and crammed a ZIF socket on to it.

I built Jed's Ped's version, so far it is my favorite modulated delay. I switched the diodes to D9E just to be cheeky.

View attachment 94638

not a bad idea!
although, is it much different to just using a previous delay build to audition PT2399s with? (i guess the ZIF sockets saves wear and tear on machined sockets on a build at least)

 

[Erik S]

(i also figured out i could just bend the pot out of the way to desolder the resistors instead of desoldering a whole pot)

Last time I had to do that I did the job top-side. Snipped the resistors at the body, grabbed the stubs with pliers, heated and pulled, then pre-cut the new resistors to length and soldered from the top. I think I did the whole thing in the box too.

 

[BuddytheReow]

Nice build. I like those hot red wires. Or is that just a lighting trick?

 

[owlexifry]

Last time I had to do that I did the job top-side. Snipped the resistors at the body, grabbed the stubs with pliers, heated and pulled, then pre-cut the new resistors to length and soldered from the top. I think I did the whole thing in the box too.

ohh hell yeah that’s probably a better way to do it. (but i’m not sure i’d be able to do it like that without burning things with the iron lol)

Nice build. I like those hot red wires. Or is that just a lighting trick?

thanks all my builds are done with 22awg solid core from tayda (i bought too much red, normally prefer white)

 

[KreoPensas]

The only benefit over using a known pt2399 based pedal is the ZIF. I can't tell you how many times I have thought I was being gentle with a socketed chip and launched it across the bench.

 

[KR Sound]

I had to be picky with the 2399, but I love this circuit.

I also bought 100 of the SMDs and plan to use these next time:

SOIC-16 Adapter - PedalPCB.com

SOIC-16 Adapter

www.pedalpcb.com